A compound having norbornane ring and perhydro dimethanonaphthalene ring skeletons is used much in heat resistance resins due to the heat resistance derived from the rigid skeletons thereof. For example, it has been reported that a heat resistance resin hardly giving thermal weight reduction can be obtained by deriving polyester from 2,5-or 2,6-norbornanedimethanol (for example, Patent Document 1).
Meanwhile, it has been demanded for a drive unit of transmission or the like that receives the driving power of an automobile to operate at a higher temperature in accordance with the tendency to increase the output of recent automobiles and miniaturize the unit itself. Especially for a mechanical traction drive unit, heat resistance for the fluid employed therein has particularly been demanded in terms of reduction in weight and manufacturing cost, and high output response.
[Patent Document 1] Japanese Unexamined Patent Publication No. 2001-64374